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BRAF V600E Mutation testing
|Performed by||Applied Genomics Laboratory|
|In House Availability||Test performed twice weekly, with DNA extraction set up on Mondays and Wednesdays, day shift only|
|Collection Instructions||In general, the tumor should be a minimum of 0.4 cm in size. Blocks selected for BRAF mutation testing must contain tumor tissue. Areas of tumor must contain at least 50% tumor cells. The lab can remove adjacent non-tumor tissue, so the entire slide does not need 50% tumor cells, just the area with tumor. Contact the laboratory (415-514-1035, AGCLab@ucsf.edu) if the specimen suitability is uncertain. Label slides with pathology case number and block identification.|
|Sample type||Formalin-fixed, paraffin-embedded tissue. Tissue block or unstained slides. If sending unstained slides, we require five (5) 10-micron tissue sections on uncharged glass slides. One adjacent H&E stained slide should be included. Cytology smears may also be used for testing if there is sufficient tumor present. Contact the laboratory (415-514-1035, AGCLab@ucsf.edu) if testing on a cytology smear is desired.|
|UCSF Rejection Criteria||All required slides not included. Insufficient tumor tissue present on slide as determined by pathologist. Slides not labeled or not accompanied by completed requisition form (if not ordered directly through Department of Pathology).|
|Normal range||No mutation detected|
|Stability||Formalin-fixed, paraffin-embedded tissues are stable indefinitely at room temperature|
|Turn around times||7-10 Business days|
|Reflex?||The test may be performed reflexively on colorectal carcinomas which show both microsatellite instability by PCR, and loss of MLH1 protein by immunohistochemistry. Reflex testing may also be performed in association with EGFR and/or KRAS mutation testing if those tests are negative for mutation|
|Additional information||An interpretation of this test by a laboratory physician will automatically be performed and billed for separately.
The BRAF Mutation Testing by Real-time PCR assay utilizes real-time PCR amplification of a portion of exon 15 of the BRAF gene using specific PCR primers. DNA is extracted from tumor tissue and amplified in the real-time PCR reaction. The amplified product is detected with a specific pair of fluorescence resonance energy transfer (FRET) probes which hybridize to the site of potential mutation at nucleotide 1799, corresponding to amino acid 600. After amplification, fluorescence from the probes is measured as the PCR products are heated to cause dissociation of the probes from the PCR products. The temperature at which dissociation occurs is dependent upon the sequence at the site of hybridization
This test detects the V600E mutation in the BRAF gene from formalin-fixed paraffin-embedded tumor tissue. BRAF V600E mutation has been shown to be present in a number of tumors, including thyroid and colorectal carcinomas, melanomas, histiocytic tumors, and certain brain tumors.
In the thyroid, presence of the mutation is associated with more aggressive clinical behavior. BRAF mutation in Lynch syndrome-associated colorectal cancers is extremely rare, and the presence of BRAF mutation is a strong indication of a sporadic (i.e., non-Lynch) colorectal cancer. However, note that not all MSI-H colorectal cancers that lack BRAF mutation are due to Lynch syndrome. BRAF V600E mutation in melanoma predicts response to vemurafenib. However, BRAF mutation in colon cancer is associated with a lack of response to EGFR therapy. BRAF mutation testing may also be useful in evaluation for EGFR therapy in lung cancer.
Results of this test should be correlated with the patient's other clinical and laboratory information. This assay is not intended to test for BRAF mutations other than the valine to glutamate substitution at amino acid position 600 (V600E). However, non-V600E mutations at or near codon 600, including V600K, V600R, c.1794_1796dupTAC (insT), and K601E may also be detected with this assay. If a non-V600E mutation is suspected, the samples will be confirmed by an additional assay.
The test was validated by the UCSF Applied Genomics Clinical Laboratory to confirm performance characteristics, in compliance with current guidelines for clinical implementation
|LDT or Mod FDA?||Yes|
|Last Updated||2/25/2014 4:28:11 PM|
If you have additional questions regarding this test, please call: 415-353-1667